ERBB2 and breast cancer: Current treatment guidelines recommend the use of multidrug chemotherapy, such as a sequential combination of an anthracycline-containing regimen and taxane or concurrent use of taxane and platinum, in combination with the anti-human epidermal growth factor receptor 2 (HER2) monoclonal antibodies trastuzumab and pertuzumab for the treatment of HER2-positive (HER2+) primary breast cancer [1, 2].